Vesicularia (C. Müller Hal.) C. Müller Hal., 1896.

Vesicularia is occasionally introduced as a lawn weed into California, especially in the area of San Francisco. It is a very non-descript plant notable for complanate leaves with very large cells and with very little differentiation of an alar region. It would most likely be confused for Plagiothecium, but the presence of filamentose pseudoparaphyllia, non-decurrent leaves and the lack of an hyaloderm contradict such an assumption. The median laminal cells are short hexagonal with cell width mostly more than 20 µm, much broader and relatively shorter than any Plagiothecium.
see key to Hypnum Etc.